The number of species and strains of bacteria resistant to antibiotics and the number of antibiotics to which they are resistant has increased world-wide. As a result, infections that had been readily treatable by antibiotics may no longer be so. Increased resistance of bacterial infections to antibiotic treatment has now become a generally recognized medical problem.
Throughout the developed world there is public and governmental concern about the increasing prevalence of antimicrobial resistance to antibiotic therapy in bacteria that cause diseases in humans. Many pathogens exist for which there are few effective treatments, and the number of strains resistant to available drugs is continually increasing. New antimicrobial agents and improved methods are thus needed for the treatment and prevention of infections by such pathogens.